LAS VEGAS - It was just 29 months ago that Manny Pacquiao was face-down on the canvas at the MGM Grand Garden Arena, knocked out cold and unmoving by a punch from Juan Manuel Marquez. Not only were visions of an epic meeting with Floyd Mayweather Jr. dead, but some at ringside wailed out of fear that Pacquiao would not survive that blow.

Unimaginably, Pacquiao not only has lived to fight another day but will step into that same Grand Garden ring Saturday night to face Mayweather in what has blown up into the richest prizefight in history. Projections are for revenues to go far north of $300 million, with the fighters' eventual purses approaching $180 million to $200 million for Mayweather and possibly $120 million for Pacquiao.

Questions that boxing fans have been asking for five years since the bout first was proposed finally will be answered. Mayweather (47-0, 26 KOs) enters as a clear favorite over Pacquiao (57-5-2, 38 KOs) despite the problems presented by the Filipino's southpaw style.

If any fighter of this generation has the ability to penetrate Mayweather's unyielding defensive armor, it is Pacquiao with his combination of speed, power and odd angles. But as the self-styled "The Best Ever,'' Mayweather disdainfully brushed aside the notion that Pacquiao might upset him.

"I think everybody's game plan is to come forward and throw a lot of punches,'' Mayweather said. "They think it works. It hasn't worked out of 19 years for 47 fights.''

But rather than take the air out of the fight with his elusive defense, Mayweather seems to be gearing up for an offensive attack that could put to rest all questions about his supremacy. The reason is Pacquiao's devastating loss to Marquez, a counterpuncher whose skills pale next to Mayweather's mastery.

"I think about when he fought Marquez and I fought Marquez," Mayweather said, referring to his overwhelming unanimous decision over Marquez in 2009 and Pacquiao's three contentious fights with Marquez before the KO loss. "I truly believe I'm the smarter fighter. He would be a better fighter if he wasn't so reckless. It's a gift and a curse. It's a gift to where he's won a lot of fights by being reckless. But also, you can be reckless and get knocked out. Getting knocked out in a harsh way can affect you in the long run.''

Pacquiao trainer Freddie Roach has listened to KO predictions by trainer Floyd Mayweather Sr. and observed Mayweather's strength gain. "Floyd put a lot of muscle on,'' Roach said. "I'm hoping he comes out to knock us out in the early rounds.''

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Roach noted that Pacquiao broke down video for the first time and proposed strategy to his trainer. "We're not focusing on one strategy or technique, but more than two or three strategies,'' Pacquiao said. "If he wants to fight me, that's good for me. If he wants to be running and running, moving around the ring, we are really prepared for that.''

In his three wins since being starched by Marquez, Pacquiao has looked none the worse after such a traumatic loss. Roach said he knew Pacquiao was going to be all right when he wanted to wash the blood off his face before taking the ambulance to the hospital.

In a sense, Pacquiao's advantage is that he knows what it is like to lose and come back at the top of his game. The pressure is on Mayweather, whose last three wins have been strongly contested, to preserve his undefeated record. If he gets out of his comfort zone going for a spectacular KO, a real fight might break out.

The hunch here is that Pacquiao will take an early lead and win enough of the late rounds to eke out a historic upset.